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[1] The Paleocene Eocene Thermal Maximum (PETM) coincided with a negative carbon isotope excursion (CIE) in carbonate and organic matter, in terrestrial and marine records. Consequently the PETM global warming of 5-6°C has been attributed to the rapid emission of a large amount of isotopically light carbon into the ocean-atmosphere system, and the magnitude of the CIE has been used to estimate the amount of carbon greenhouse gas emitted. However, there are large discrepancies between the magnitude of the CIE in marine and in terrestrial material, in different types of marine carbonate records (bulk carbonate, planktic and benthic foraminiferal carbonate), and in marine carbonate records from different locations. The marine carbonate record of the CIE may be incomplete in most deep-sea (bathyal-abyssal) locations because of ocean acidification and widespread dissolution of seafloor carbonates. We demonstrate that the CIE in benthic foraminiferal stable isotope records is relatively abrupt and not as gradual as portrayed in bulk carbonate records along the Walvis Ridge depth transect (SE Atlantic). The benthic CIE is about À1.5% at 3600 m paleodepth, in contrast to about À3.5% at 1500 m paleodepth, consistent with depth-dependent truncation by carbonate dissolution. Strong covariance between the benthic record and the stable carbon isotope values of terrestrial n-alkanes isolated from the same core (i.e., Site 1263) supports a relatively rapid excursion of at least À3.5% but no more than À5.0%.

We have studied Leo A -the isolated and extremely gas rich dwarf irregular galaxy of very low stellar mass and metallicity. Ages of the stellar populations in Leo A are ranging from ∼10 Myr to ∼10 Gyr. Here we report the discovery of an old stellar halo and a sharp stellar edge. Also we find the distribution of stars extending beyond the gaseous envelope of the galaxy. Therefore, Leo A by its structure as well as stellar and gaseous content is found to resemble massive disk galaxies. This implies that galaxies of very low stellar mass are also able to develop complex structures, challenging contemporary understanding of galaxy evolution.

We report the detection of a faint old stellar system at (SDSS J1257ϩ3419), based on (a, d) p (194Њ .29, 34Њ .32) the spatial distribution of bright red giant branch stars in the Sloan Digital Sky Survey Data Release 4. SDSS J1257ϩ3419 has a half-light radius of pc and an absolute integrated V magnitude of magat a heliocentric distance of kpc. A comparison between SDSS J1257ϩ3419 and known Galactic halo 150 ‫ע‬ 15 objects suggests that SDSS J1257ϩ3419 is either (1) a faint and small dwarf galaxy or (2) a faint and widely extended globular cluster. In the former case, SDSS J1257ϩ3419 could represent an entity of a postulated subhalo of the Milky Way. Further photometric and dynamical study of this stellar system is vital to distinguish these possibilities.

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